Microsoft had this to say about the recent change:
"We're rolling out this preview of E2EE for unscheduled one-to-one calls today. When both parties in a one-to-one call turn on E2EE, the communication between those two parties in the call is encrypted from end-to-end. No other party, including Microsoft, has access to the decrypted conversation."
"With this release only the real-time media flow, that is, video and voice data, for one-to-one Teams calls are end-to-end encrypted. Both parties must turn on this setting to enable end-to-end encryption."
By default the new feature is disabled but IT admins will be able to toggle the new feature on either for the organization as a whole or for specified user groups.
If you are an admin here's how you make end-to-end encryption calls available:
Users will need to be running the latest Teams update and will need to turn on end-to-end encryption in their Teams settings.
Users can do this by following these simple steps:
It's an excellent addition. Give it a try at your next convenience.